Fabrication method and the monolithic binary rare-earth-aluminum, REE-Aloy, matrices thereof

ABSTRACT

This invention relates to a system of monolithic binary rare-earth element (REE)-aluminum (Al) intermetallic alloy series of mass composition range of 30 wt %&lt;REE&lt;85 wt %, where REE=Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Lu and, the general methodology to fabricate any monolithic binary rare-earth-element aluminum matrix thereof. The alloys system consists of 15 unique advanced series, each based on an individual REE=Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Lu. Each series defines a range of monolithic binary rare-earth-element-aluminum matrices generally defined as REE-Aloy xxyy. It is observed that when a rare-earth element (REE) is alloyed with aluminum in the relatively comparable ratios from 30 wt % REE to 85 wt % REE, it exhibits superior alloys qualities. The overall quality of the alloy formed is vastly improved beyond both the REE and aluminum. Optimally, all REE-Aloy series are comparable or advantageous in one way or another to aluminum, steel, and titanium alloys for multiple application technologies including, advanced alloys, permanent magnets, nuclear energy, and microwave engineering. The impact of REE-Aloy advanced material can revolutionize the course for the necessary technologies to achieve the goal outlined in the renewed agreement under the Paris Convention to address climate change and green energy. For showcases of this invention, high-purity prototypes of monolithic binary neodymium-aluminum (i.e., REE-Aloy 6000 series) and samarium-aluminum matrices (i.e., REE-Aloy 6200 series) obtained in large quantities establishes efficient production. Determined by STEM and HRTEM analyses, the REE-Aloy 6062 (i.e., 62 wt. % Nd—Al) is an [Al+Nd5Al11] intermetallic matrix, and the REE-Aloy 6267 (i.e., 67 wt. % Sm—Al) is an [Al+SmAl4] were invented. Both REE-Aloy 6062 and REE-Aloy 6267 alloys exhibit significantly improved thermo-mechanical and physical stability and corrosion-resistant properties beyond the respective REE and Al. Long range order, evident for crystalline solids, is revealed by the HRTEM diffraction patterns for the REE-Aloy 6267 intermetallic species. After further heat-treatment, REE-Aloy 6062 and REE-Aloy 6267, REE-Aloy 6079, and REE-Aloy 6277 were produced. From observations, the REE-Aloy 6267 and REE-Aloy 6079 were deduced to be exclusive NdAl2 and SmAl2 intermetallic phases, respectively. REE-Aloy 6079 and REE-Aloy 6277 alloys achieve the maximum thermo-mechanical stability comparable to steel and titanium. Robust corrosion resistance for the REE-Aloy 6000 and 6200 alloy series are revealed by the presence of the respective surface REE-aluminate (REExAlyOz) using HRTEM and STEM electron-energy-loss spectrum analyses (EELs). A similar outcome is expected for all other REE-Aloy series. A description of the invention is presented in full detail.

BACKGROUND

The rare earth elements (REEs) make up a series of 17 unique metals, (where, REE=Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) with particular properties and, except for promethium (Pm), are used in most common and everyday equipment. The use of REEs in the electronic components of many high-tech devices. A list of devices includes smartphones, digital cameras, computer hard disks, fluorescent and light-emitting-diode (LED) lights, flat-screen televisions, computer monitors, and other electronic displays. Important industrial uses of rare-earth elements (REEs) include reaction catalysts, rechargeable batteries, phosphors, permanent magnets, reactor control rods as neutron absorbers, and alloying. Until now, REEs usage in some of these essential industrial applications (primarily in permanent magnets, as control-rods neutron absorbers and pressure vessels for reactors, and in alloying) are severely limited due to their innate chemically reactive characteristics. USGS [1] 2017 data shows a breakdown in the use of the REEs that only a 10% usage is for metallurgy and alloying in the US. In addition, when they are used as constituents in alloying, they are typically less than 3 wt %, yet having improvement effects. However, due to this invention, it is possible to explore the potentially revolutionary impact of REEs in advanced alloy technology. The innovations described here can even charter the course for the necessary technologies to achieve the goal outlined in the agreement under the Paris Convention to address climate change and advancement in green energy. In particular, Article 4 and Article 10 under the Paris Agreement make provisions for exploring this REE technology by considering the necessity of having available the best science and implementing the latest related innovative technologies, respectively, to impact climate change and sustain green energy globally.

Since REE chemistry is very similar, a particular disadvantageous chemical characteristic for one REE is effectively observed for all. Even in cold water, the chemical instability of REEs in their pure form makes them unsuitable for direct application technologies. For instance, their use in metallurgical applications is mostly absent primarily due to their characteristic readiness to oxidize forming weak metal-to-oxide bonds which makes them prone to corrosion. REE reactions with water cause hydrogen to liberate even in ambient (i.e., cold) conditions. Aluminum also has the potential for the hydrogen-producing reaction and corrosion but not as readily as the REEs. Aluminum naturally forms a relatively firm protective oxide layer (Al₂O₃) on the surface to prevent corrosive attacks. The aluminum (III) oxide layer mitigates corrosion reactions from taking place in ambient or even in hot water conditions. Thus, the robust metal-to-oxide bonding gives aluminum significant advantages for industrial applications considering its low melting point. However, there are limitations in metallurgy applications as the aluminum (III) oxide (Al₂O₃) layer is thin and is removable in weak acidic environments. Table 1.0 shows a comparison of the list of fifteen (15) REEs considered in this invention to aluminum, steel and titanium. The first data column shows the electronegativity, where the smaller REEs (those above Er) is slightly more reactive. Their oxidations states are in Column 2, for which all are exhibit +3 similar to aluminum. Column 3 shows formation energies for the lowest-energy binary ground state this invention (REE-Aloy) intermetallic phase (i.e., the ReeAl₂). The negative sign reveals that the process is exothermic and favors forming a monolithic binary intermetallic phase [2-3].

The mechanical qualities of the REE-Aloy alloys are improved significantly beyond the REE and Al due to the formation of very stable binary intermetallic phases. Also, the corrosion resistance of REE-Aloy alloys is greatly improved beyond the REE and aluminum due to the formation of robust garnet-type and perovskite-type Ree-aluminate (REE_(x)Al_(y)O_(z)) surface layers. There are significant improvements in thermo-mechanical stability (i.e., melting points). That is, the melting points of the ReeAl₂ phase [4-6] are listed in Column four (4), while those of the individual REEs and aluminum are presented in Column five (5). Compared to Al and most of the REEs the predicted thermo-mechanical stability of the ReeAl₂ binary phases is superior. For the REEs Tm, Er, Lu, Sc, and Y (i.e., those REE with melting points higher than carbon steel and slightly less than titanium), respectively, their ReeAl₂ phase melting points are superior to Al, but only marginally less than their pure forms. Overall, the range of melting-point temperatures presented in Table 1.0 for all ReeAl₂ phases is significantly elevated and immediately comparable to carbon and stainless steel (i.e., 1375° C.-1538 C) and slightly less than titanium alloys (1668° C.).

TABLE 1 A List of Chemical and Physical Properties Comparisons for REEs, Aluminum, Titanium, Steel and REE-Aloy REE Pauling REE REE-Al Ree-Aloy REE RE Scale Oxidation lowest ΔH_(f) Ree-Aloy Max. Melting Melting Element Electronegativity State ev/atom Series ID Temp ° C. Temp ° C. La 1.1 +3 −0.523 5700 1405 920 Ce 1.12 +3, +4 −0.564 5800 1480 795 Pr 1.13 +3 −0.574 5900 1480 935 Nd 1.14 +3 −0.501 6000 1460 1024 Sm 1.17 +3 −0.57 6200 1480 1072 Eu 1.2 +2, +3 0.396 6300 1050 826 Tb 1.2 +3 −0.303 6500 1513 1356 Dy 1.22 +3 −0.52 6600 1508 1407 Ho 1.23 +3 −0.516 6700 1529 1461 Er 1.24 +3 −0.509 6800 1446 1529 Tm 1.25 +3 −0.502 6900 1500 1545 Yb 1.1 +3 −0.409 7000 1355 824 Lu 1.27 +3 −0.484 7100 1580 1652 Sc 1.36 +3 −0.497 2100 1420 1541 Y 1.22 +3 −0.554 3900 1490 1526 Pauling Metal Alloy Element Scale Oxidation ΔH_(f) Ree-Aloy Melting Melting Element Electronegativity State ev/atom Series ID Temp ° C. Temp ° C. Al 1.61 +3 — — — 660 Fe 1.83 +2, +3, +6 — — 1375-1530 (steel) 1538 Ti 1.88 +2, +3, +4 — — 1650 1668

Monolithic binary REE-aluminum alloys of mass ratios of 30 wt %<REE<85 wt %, (REE-Aloy) have extensive commercial research and industrial potential. These innovative alloys series either preserve or improve the characteristic mechanical qualities of the REE and aluminum while mitigating their disadvantageous characteristics. Therefore, the articles of this invention (i.e., each REE-Aloy series) possess unparallel potency for versatility. Patents CN101906604B, U.S. Pat. No. 5,037,608A, CN103924127A, U.S. Pat. Nos. 3,490,900A, 2,771,369, 4,108,645A, and 7,854,252B2 are all inventions that utilize REEs in metallurgy and alloying but does not constitute the claims listed in this invention. As advanced alloy technology for general industrial metallurgical usage, each REE-Aloy alloy series can have, optimally, thermo-mechanical stability that is immediately comparable to carbon steel while having as low as 40% the weight e.g. the REE-Aloy 2100 and 3900 series. Although titanium alloys have a slightly higher melting point than the series of the REE-Aloy alloy system, the formability and wielding issues of titanium may still make it a less advantageous option than the REE-Aloy alloy system.

For specific applications in nuclear reactor facilities such as control rods and spent-fuel storage technology, many REEs have the tremendous neutron-absorbing capacity necessary for safely controlling fission. For reactor containment-vessel material application, many REEs have the neutron-transparent characteristics for mitigating radiation damage, having low end-of-service dose and waste concerns. But, this quality is made ineffective by their disadvantageous intrinsic chemically reactive tendencies with water. The use of rare earth elements in magnet technology has vast industrial and electronic applications ranging from electric vehicles to renewable energy production. Examples are neodymium-iron-boron and samarium-cobalt, two of the most powerful type of permanent magnets. However, limitations in the applications of rare-earth magnets are generally defined by their inherent disadvantages. Rare earth permanent magnets, in particular, are well-known to have poor resistance to high temperature and corrosion and are fragile (i.e., brittle).

SUMMARY

The invention details are of the 15 series of REE-Aloys alloys which constitutes a system of monolithic binary rare earth element (REE)-aluminum (Al) matrices with the REE mass-ratio range of 30 wt %<REE<85 wt %, where REE=Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Tb, Dy, Ho, Er, Tm, Yb, Lu) and, the fabrication method of any binary REE-aluminum within the same mass-ratio range. All the matrices of any REE-Aloy alloy series consist of REE-Al intermetallic phases that may or may not be dispersed in aluminum. For demonstrations of the invention, four articles of the innovative REE-Aloy alloy technology were produced in high purity to demonstrate. In particular, the fabrication of two unique matrices of the REE-Aloy 6000 (neodymium-aluminum) series and two of the REE-Aloy 6000 alloy (samarium-aluminum) series, respectively, is described in detail. Neodymium and samarium are classified as light REEs and are only slightly less chemically reactive than Lanthanum. Therefore, although they are slow to react with cold water, they react readily with hot water or steam to produce hydrogen gas. They also ignite spontaneously in air at elevated temperatures (above 150° C.) to forms the neodymium and samarium (III) oxide (i.e., Nd₂O₃ and Sm₂O₃). However, REE₂O₃ typically forms weak surface bonds thus, easily flakes off and continually exposes the metal to more corrosion. However, REE-Aloy interactions with oxygen (O) can produce garnet and/or perovskite-type aluminates that robustly bond to the metal surface which, drastically reduces corrosion reactions. Thus, one of the most unique features of REE-Aloy alloys technology is the characteristic to inhibit corrosion reactions similar to aluminum.

At elevated temperatures, neodymium and samarium reactions are instantaneous. At temperatures above 1100° C., neodymium and samarium almost instantaneously form binary compounds with carbon, silicon, and oxygen. Although this characteristic can severely affect the purity of REE-Aloy alloys, it is essential for the invention. The reaction between REEs and aluminum is exothermic above 1100° C. which, forms Re-Al intermetallic phases. Neodymium and samarium, along with all REEs are also potent reducing agents. For comparison, Table 1. shows that neodymium and samarium are much more reactive than aluminum, where their Pauling scales are 1.14 and 1.17, respectively, whereas aluminum is 1.61. Therefore, they readily reduce most metals in compounds to the elemental form. However, this characteristic is also advantageous for the REE-Aloy fabrication process described in this invention.

Mechanical properties such as density and melting-point were measured for the alloys created. Using the mass densities of the invented alloys, REE-Aloy 6062 and 6079 and, REE-Aloy 6267 and 6277 were identified. Although REE-Aloy 6062 and REE-Aloy 6267 prototypes are observably tough, they retain enough ductile and malleable qualities; thus, still easily machined. Although REE-Aloy 6062 and REE-Aloy 6267 matrices are not optimal, they possess enhanced thermo-mechanical properties significantly beyond aluminum. That is, REE-Aloy 6062 and REE-Aloy 6267 melt at 1250° C. and 1300° C., respectively. Their thermal expansions are observed to be less significant than aluminum. However, additional heat processing transformed REE-Aloy 6062 and 6267 to REE-Aloy 6079 and, REE-Aloy 6277 matrices, respectively. Alloys REE-Aloy 6079 and 6277 were deduced to be exclusive ReeAl₂ intermetallic alloy. Observably, REE-Aloy 6079 and REE Aloy 6277 are significantly more mechanically robust.

For all other exclusive ReeAl₂ REE-Aloy excepting EuAl₂, the melting temperature for all ReeAl₂ alloy is predicted to range from 1355° C. to 1580° C., which is immediately comparable to carbon or stainless steel and, slightly less than titanium alloys. EuAl₂ is predicted to melt at 1050° C., which is still much higher than aluminum and europium. Additionally, each naturally produces robust neodymium and samarium aluminate with general formula REE_(x)Al_(y)O_(z), protective surface layers, respectively, to prevent corrosion in the same way aluminum oxide coats its metal surface. Therefore, the corrosion resistance experiments with ambient and boiling water conditions and acidic environments were conducted. The neodymium and samarium aluminate surface layers cause the REE-Aloy alloys to be effectively chemically inert in air, cold water, boiling water, and for some even much-delayed interactions in hydrochloric acid (HCl). It is observed that the corrosion resistance of REE-Aloy 6062 and REE-Aloy 6267 is significantly enhanced compared to aluminum and the respective REEs.

Electron microscopy measurements for the invented alloy compositions revealed crystallographic details for REE-Aloy 6062 and REE-Aloy 6267. The formation energies of all REE-Aloy phases formed are negative but, the three stable ground state phases ReeAl₃, ReeAl₂, and ReeAl are the lowest. NdAl₂ and SmAl₂ have the lowest formation energies compared to the other ground states of −0.501 eV/atom and −0.570 eV/atom Refs [2-3] of their three stable ground state phases, respectively. At 62 wt. % neodymium in aluminum (i.e., REE-Aloy 6062) and 67 wt. % samarium in aluminum (i.e., REE-Aloy 6267), each matrix possesses a particular REE-Al intermetallic phase mixed with aluminum. STEM and HRTEM reveals that the REE-Aloy 6062 alloy matrix is consists of Al+Nd₅Al₁₁ intermetallic phase and the REE-Aloy 6267 is a matrix consists of Al+SmAl₄ intermetallic phase. A process of additional heat treatment to both REE-Aloy 6062 and REE-Aloy 6267 matrices convert both to the optimal forms of each series as REE-Aloy 6079 and REE-Aloy 6277 alloys, deduced to be exclusively NdAl₂ and SmAl₂ intermetallic phases, respectively. The formation of various REE-Al intermetallic based on the REE mass composition in an exclusive aluminum environment is expected to be similar for all REE-Aloy series of this invention.

DESCRIPTION OF DRAWINGS AND PHOTOGRAPHS

FIG. 1.1 The complete experimental setup and stepwise REE-Aloy alloying process

1. Specialized multi-layered melting vessel

2. Induction heating coils

3. 90% Ar-10% CO₂ or Ar gas mixture Inlet

4. Enclosed 90% Ar-10% CO₂ or Ar Atmosphere

5. Tungsten stirrer

6. Aluminum samples

7. (REE) samples

FIG. 1.2. A customized multi-layered melting vessel, used for REE-Aloy fabrication.

8. Outer Silicon dioxide (SiO₂) induction coil isolation vessel

9. Air-gap insulation layer

10. Graphite heating vessel

11. Alumina (Al₂O₃) reaction vessel

12. REE-aluminate (REE_(x)Al_(y)O_(z)) coat

FIG. 1.3. Casted REE-Aloy 6000 series (left) and REE-Aloy 6200 (right).

FIG. 1.4(a) Polished neodymium aluminum REE-Aloy 6062 and samarium aluminum REE Aloy 6267 next to (99.999%) aluminum.

FIG. 1.4(b) samarium-aluminum REE-Aloy 6277 (i) and neodymium-aluminum REE-Aloy 6079 (ii) after heat-treatment of REE-Aloy 6267 and REE-Aloy 6062. The white residue on the surfaces is aluminum oxide formed from burning unreacted aluminum during heat treatment. REE-Aloy 6277 and 6079 are exclusively SmAl₂ and NdAl₂ intermetallic phases, respectively.

FIG. 1.5.(a) Images taken after 10 days from experimenting with interactions of cold-water to produce hydrogen where aluminum is case-reference. Image (i) shows no interactions of REE-Aloy 6062 sample with cold-water; image (ii) shows no interactions of REE-Aloy 6267 sample with cold water; image (iii) shows significant interactions of neodymium and samarium samples with cold water. Aluminum appears to interact with cold-water in the presence of the reacting neodymium and samarium samples.

FIG. 1.5.(b) Images after five (5) minutes of experimenting with interactions of hot water (70° C.-95° C.) to produce hydrogen where aluminum is case-reference. The image shows instantaneous interactions in hot water only for the neodymium and samarium samples.

FIG. 1.6.(a) i. A low (1) resolution STEM scan of a region of the REE-Aloy 6062 matrix which, includes four individual grain structures labeled G1-G4. The distinction between pure (i.e., the unreacted) and the intermetallic Nd—Al phases are shown as the lighter contrast region (G2) being pure aluminum and G1, G3 and, G4 being Nd—Al intermetallic phases.

FIG. 1.6.(a) ii. STEM EDS element contrast images showing the distinction between the grain region of aluminum, G2, and the grain regions of the Nd—Al intermetallic phases (G3).

FIG. 1.6.(a) iii. A comparison of EDS from region G3 and G2 which, suggests pure Al in region G2 and Nd—Al intermetallic in grain region G3. The EDS Quant from region G3 shows an atom percentage of Nd and Al which suggest NdAl₂ intermetallic phase formation. The EDS spectrum confirms the Nd—Al phase in grain region G3.

FIG. 1.6.(a) iv. Pure aluminum is confirmed in grain region G2 using electron diffraction and HRTEM imaging. The peak at 1000 eV in electron energy loss spectrum (EELS) also shows only the presence of aluminum in grain region G2.

FIG. 1.6.(a) v. Electron diffraction and HRTEM imaging of grain region G3 suggesting the NdAl₄ phase from the [201] grain axis.

FIG. 1.6.(a) vi. Electron diffraction and HRTEM imaging from the same grain region G3 taken along a different grain axis that cannot be indexed with NdAl₄ diffraction patterns.

FIG. 1.6.(a) vii. Surface layer analysis showing fine grain structures resulting from mechanical grinding of the sample surface. Electron diffraction analysis of the selected fine-grain surface layer region similarly suggests the NdAl₄ phase as grain region G3. A comparison of the chemistry in the selected fine grain region and in grain region G3 using EELS suggests that there is no difference in the elemental composition or bonding.

FIG. 1.6.(b) i. The EDS maps from STEM analysis of of REE-Aloy 6267 showing regions of pure aluminum and, Nd—Al intermetallic phase confirmed by EDS QUANT data from the boxed area 1.

FIG. 1.6.(b) ii. The TEM analysis of the boxed region 1, in FIG. 1.6.(b) i. using HRTEM and electron diffraction confirming SmAl₄ for zone axis [11-3].

FIG. 1.6.(b) iii. The TEM analysis of the boxed region 1, in FIG. 1.6.(b) i. using HRTEM and electron diffraction confirming SmAl₄ for zone axis [33-1].

FIG. 1.6.(b) iv. The TEM analysis of the boxed region 1, in FIG. 1.6.(b) i. using HRTEM and electron diffraction confirming SmAl₄ for zone axis [2-10].

FIG. 1.6.(b) v. The TEM analysis of the boxed region 1, in FIG. 1.6.(b) i. using HRTEM and electron diffraction confirming SmAl₄ for zone axis [53-1].

FIG. 1.6.(b) vi. Multi-beam bright field image showing fine grain structure in the sample surface.

FIG. 1.6.(b) vii. Image showing HRTEM analysis (first panel) and three (3) EELs spectra from STEM analysis of the fine-grain structure close to the sample surface at points 1, 2, and 3. The presence of oxygen [O], which suggest the oxidized Sm—Al intermetallic grain is only observed for the spot's 1 and 2 closer to the surface.

FIG. 1.7. Flow diagram of the transmutation of samarium-149 into nuclides of europium and gadolinium from neutron irradiation and radioactive decay.

Table 1.1 List of Recovered Masses for each REE-Aloy Prepared

Table 1.2. List of Properties for the Prepared REE-Aloy 6062 & 6079, REE-Aloy 6267 & 6277 Alloys.

Table 1.3. Corrosion Tendencies for Al, REE-Aloy 6062,6079, 6267 and 6277, Sm and Nd.

DESCRIPTION OF FABRICATION METHOD AND THE INVENTED REE-ALOY MATRICES 1.1 Introduction

The general nomenclature of monolithic binary rare-earth-element (REE)-aluminum (Al) alloy invention consisting of 30 wt %-85 wt % REE-Al is defined as REE-Aloy ‘xxyy’, where the xxyy, a four-digit identification number defining the particular REE (i.e., the atomic number) and its mass composition and, REE=Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Lu. The four-digit identification number given to a matrix prepared within its respective REE-Aloy series is defined as follows: the first two digits (“xx”) denote the REE atomic number and the last two define its mass percent composition in the alloy. The “yy” nomenclature defines a mass percent composition but a “00” denotes the particular REE-Aloy series as a whole. Therefore, the examples used to demonstrate this invention are the REE-Aloy 6000 and 6200 series. Thus, two different monolithic binary REE-aluminum alloy series consisting of 30 wt %-85 wt % neodymium-aluminum (REE-Aloy 6000 series) and consisting of 30 wt %-85 wt % samarium aluminum (REE Aloy 6200 series) were invented in relatively quantities (i.e., between 30 g-100 g samples). The alloys were prepared from stock materials of 99.9% pure neodymium and 99.99% pure samarium granules [7-8], and 99.999% pure aluminum metal pellets [9] from American Elements. The remaining impurities within the neodymium and samarium stocks are mostly other lanthanides. The most significant impurity within the aluminum and neodymium metal is iron (Fe) at 1.701 ppm and 1225.8 ppm, respectively. The work accomplished thereof was performed at Ara-Neuk LLC.

1.2 Experiment Instrumentations

In this invention, heating was provided by a 15 KHz mid-range frequency induction heater from Across International®. A high-precision OHAUS Pioneer™ electronic balance was used to accurately weighted masses of aluminum and neodymium and samarium, according to the intended alloy weight-percent constituent was utilized. The apparatus also included a customized multi-layered melting reaction vessel, particularly configured for the invention. The melting-reaction vessel is housed under an atmosphere of pure argon for oxygen displacement. FIG. 1.2 a, and, FIG. 1.2b (i) and (ii) show stepwise drawings of the invention's REE-Aloy alloying process.

The meltingreaction vessel configured for the experiments which constitute the invention is specifically designed with four annular layers. The first is a SiO₂ outer layer that isolates the induction coils; next, an air gap for low heat transfer; then a graphite layer for high-temperature retention heating, and innermost pure alumina (Al₂O₃) high-temperature reaction vessel. The first three layers (i.e., the SiO₂-air-graphite) acts as flask-furnace which, maintains the core of the melting vessel (i.e., the reaction vessel) at temperatures for relatively long periods when the heater is off. Within the reaction-vessel is where the exothermic REE-aluminum reactions take place in their liquified state to produce high-purity REE-Aloy alloys.

1.3 Fabrication Method for High-Purity REE-Aloy 6000 and 6200 Alloy Series

For the initial (i.e., first-stage) preparation of the REE-Aloy 6000 and 6200 series, the following steps were performed:

(1) In a pure argon atmosphere in a housing chamber, the multi-layered melting vessel described in FIG. 1. was heated by induction.

(2) A precisely known quantity of aluminum was added and liquefied within the alumina (Al₂O₃) reaction vessel at the core of the melting vessel, and heating of the liquid aluminum continued until its temperature reached {tilde over ( )}100° C. below the melting point of REE to be alloy.

(3) At {tilde over ( )}100° C. below the melting point of REE, the heating was discontinued, and the addition of the REE proceeds cautiously under argon, while the temperature of the liquid aluminum remained above 850° C. within the core of the melting vessel.

(4) After adding the REE, heating resumed and, the mixture was homogenized using a tungsten (rod) stirrer. The objective of these first steps is to enable a special coating to form on the interior surface of the reaction vessel for high purity REE-Aloy production.

(5) Heating continued up to 100° C. beyond the melting point of the REE. Using the tungsten rod, stirring followed so that the liquid REE-Aloy coats the inner surface of the reaction vessel. This step allows a robust REE-aluminate (REE_(x)Al_(y)O_(z)) layer to form between the REE-Aloy coat and the alumina vessel surface thus, completes the reaction vessel for the master alloying process. The formation of the REE-Al—O layer on the interior surface of the reaction-vessel is facilitated by taking advantage of both a reducing interaction of the REE on the alumina (Al₂O₃) walls and the exothermic REE interaction with liquid aluminum. The melting point of the REE-aluminate is usually greater than 2000° C. Alumina was particularly selected as the core reaction vessel material for this detail. It is an essential step that is unique to this invention for high-purity REE-Aloys production.

(7) Heating is discontinued and, the new layer on the reaction-vessel interior is allowed to cool for 10 mins. The new ceramic layer that permanently coats the inside of the reaction vessel allows only for REE-Al interactions to occur during the main alloying steps.

(8) Within the Ar atmosphere, heating of the newly coated reaction vessel resumed and followed by the addition of the specific mass of aluminum in the composition ratio to be alloyed.

(9) In preparation for the REE-aluminum reaction, the mass of aluminum was liquefied, and heating continued up to {tilde over ( )}100° C. less than the melting temperature of the REE before discontinuing heat.

(10) Heating was discontinued followed by cautiously adding of the mass of REE under argon atmosphere to the liquefied aluminum while the temperature is between 850° C. and the melting temperature of the REE.

(11) Heating resumed and continued until the liquid REE-Aloy alloy was at a temperature that exceeds the REE melting point.

(12) Next, the liquid REE-Aloy alloy was cautiously stirred using a clean pure ground tungsten stirrer rod to aid homogenization and complete all Ree-Al reactions. The liquid alloy was allowed to settle for about 10 mins while the heating continued before removing the entire melting vessel from the induction coil. Casting the liquid alloy in a graphite mold to cool then quenching in water were the final steps.

Table 1.1 lists the masses of the initial Nd, Sm, and Al samples, recovered for two REE-Aloy 6000 and two REE-Aloy 6200 samples prepared. For the four samples prepared, the average recovery for the two REE-Aloy 6000 samples is 60%. Between 30%-40% of the Nd—Al melt remained adhered within the reaction vessel after casting. The average recovery for the two REE-Aloy 6200 samples is 75%. Between 20%-25% of the melt remained within the alumina vessel after casting the alloy. FIG. 1.3. shows an image of freshly prepared REE-Aloy 6000 and REE-Aloy 6200 samples.

Additional (i.e., a second-stage) heat treatment steps were done, individually, for a portion of the initially prepared REE-Aloy 6000 and REE-Aloy 6200 samples each. The purpose of heat-treating each of the freshly prepared REE-Aloy 6000 and 6200 samples was to experiment on a process to obtain REE-Aloy matrices that are purely ReeAl₂ intermetallic phases. In the pure ReeAl₂ intermetallic phase, the REE-Aloy alloys achieve their maximum thermo-mechanical stability [4, 5 and 6]. First, the temperature within the vessel was raised to 1200° C. Next, the samples were individually heat-treated within the melting-vessel in an ambient (i.e., air) atmosphere unperturbed up to 1400° C. before testing for softness by piercing using a 2.4 mm×175 mm pure ground tungsten rod. After testing for softness, heating continued up to 1500° C. for signs of liquefication.

1.4 Mechanical Properties Measurements and Machining Capability

The exact four-digit REE-Aloy identification for each alloy prepared was determined after obtaining the density. The water-displacement technique determined the densities of aluminum, the first-stage prepared, and also the second-stage heat-treated REE-Aloy 6000 and 6200 samples, neodymium, and samarium samples. Each density reported is the average of n=3 unique measurements. The sample-displaced water volumes and metal masses were measured using a precision B© 1 ml TB Syringe and a high-precision OHAUS Pioneer™ electronic balance, respectively. The measured densities for aluminum, neodymium, and samarium are consistent with known theoretical values. For the pre-heat-treated and heat-treated REE-Aloy 6000 and REE-Aloy 6200 alloys, the measured densities are 4.35 g/cc and 4.73 g/cc, and 5.27 g/cc and 5.38 g/cc, respectively. The specific four-digit identification for each REE-Aloy sample was determined by back calculating the required RE-Al mass ratio corresponding to the volume percentages of the REE and Al that would yield the measured density. It was found that in the pre-heat-treated RE E-Aloy samples the mass fraction for Nd and Sm are 62% and 67%, while for the heat-treated samples, 77% and 79%, respectively. The pre-heat-treated samples identify as REE-Aloy 6062 and REE-Aloy 6267, and the heat-treated as REE-Aloy 6079 and REE-Aloy 6277. FIG. 1.4(a) shows an image of the polished REE-Aloy 6062, REE-Aloy 6267 and, aluminum for comparison.

Melting points for the alloys prepared were measured using an infrared HOLDPEAK HP-1800® Profession Nine Laser Pointer Pyrometer. The thermometer measures a range of temperatures from −50° C. to 1800° C. Measuring the melting point of the 99.999% aluminum stock was essential for verifying the thermometer's accuracy. A temperature of 660° C. was recorded at the melting point of the aluminum samples, which is consistent with a well-known reference value of 660° C. Melting-point measurements of the REE-Aloy 6062 and REE-Aloy 6267 samples were obtained during the second-stage heat-treatment experiments. Neither alloy liquefied completely like aluminum. However, both soften to the consistency of liquid-solid aggregate at 1250° C. and 1310° C. for REE-Aloy 6062 and REE-Aloy 6267, respectively. Also, before the REE-Aloy 6062 and REE-Aloy 6267 soften, relatively small quantities of unreacted liquified aluminum oozed to the surface. This evidence of a mixed solid-liquid phase is likely to be liquefied aluminum or aluminum-rich Ree-Al intermetallic phases mixed with a stable REE-Al phase. After heating continuously above 1300° C. in the ambient atmosphere (i.e., air), the liquified aluminum that oozed to the surface appeared to have oxidized by the account of a white residue. The metal hardened beyond 1425° C. which, indicated the exclusive ReeAl2 phase. FIG. 1.3c are images of the heat-treated REE-Aloy 6062 and REE-Aloy 6267 which, were reidentified as REE-Aloy 6079 and REE-Aloy 6277, respectively, after their density measurements were performed. The white residue is likely to be aluminum-oxide (Al₂O₃). FIG. 1.4b shows the final heat-treated REE-Aloy 6079 and REE-Aloy 6277 prototypes. Based on the melting points provided in Table 1.2 [4, 5 and 6], REE-Aloy 6079 and REE-Aloy 6277 are likely to consist exclusively of the NdAl₂ and SmAl₂ intermetallic phase, respectively. REE-Aloy 6062 and REE-Aloy 6267 consist of various Ree-Al intermetallic phases and unreacted pure aluminum. Table 1.2 lists the measured density (n=3) and melting points for REE-Aloys 6062, 6079, 6267, and 6277.

Properties such as thermal conductivity, thermal expansion, electrical resistivity, and those related to hardness and stress were not measured explicitly. Overall, the alloys observably have significantly improved mechanical stability (i.e., toughness and brittleness) that significantly surpassed the aluminum sample. REE-Aloy 6267 appears to be considerably harder than both aluminum and REE-Aloy 6062. However, while REE-Aloy 6079 and REE-Aloy 6277 appear to be very comparable in toughness, they are tougher than REE-Aloy 6267, REE-Aloy 6062, pure neodymium, samarium, and aluminum. Nonetheless, both REE-Aloy 6062 and REE-Aloy 6267 were observably easily machined. However, thermal conductivities for the REE-Aloy 6000 series and the REE-Aloy 6200 series are likely to decrease from aluminum as the neodymium and samarium composition increase (i.e., pure Nd=16.5 W·m⁻¹·K⁻¹ pure Sm=13.3 W·m⁻¹·K⁻¹ vs. pure Al=237 W·m⁻¹·K⁻¹). The thermal expansion is expected to decrease (i.e., pure Nd=9.6 μm·m⁻¹·K⁻¹ and Sm=12.7 μm·m⁻¹·K⁻¹ vs. pure Al=23.1 μm·m⁻¹·K⁻¹) as the neodymium and samarium composition increase. For these two REE-Aloy series, the electrical resistivity is expected to increase (pure Nd=643 n·Ω·m and Sm=0.940 μ·Ω·m vs. pure Al=26.5 n·Ω·m, respectively) as the neodymium and samarium composition increase.

1.5 Preliminary Corrosion Analysis for REE-Aloy Alloy

The corrosive tendencies for aluminum, REE-Aloy 6062 and 6079, REE-Aloy 6267 and 6277, neodymium, and samarium were tested individually by interaction with cold water (20° C.), hot water conditions (i.e., 70° C.-90° C.), and in 2.0M and 5.0M HCl acid solution (20° C.). Table 3 summarizes the observations of the reactions of the metals. Neodymium and samarium react slowly with cold water to produce hydrogen. FIG. 1.5(a) shows the evolution of hydrogen gas from neodymium and samarium in cold water over two weeks. In comparison, over the same two-week period, a reaction in water at 20° C. was not observed for aluminum, REE-Aloy 6062, and REE-Aloy 6267 as shown in FIGS. 1.5(b) and (c). Testing for corrosion in hot water conditions (i.e., 70° C.-90° C.) shows that neodymium and samarium react with hot water to produce hydrogen within minutes. However, the reaction was not observed for aluminum, REE-Aloy 6062, and REE-Aloy 6267, as shown in FIG. 1.5(d). Although, it may be necessary to perform this hot-water test over a much-extended period. The formation of the neodymium and samarium aluminate layer on the surfaces of REE-Aloy 6062 and REE-Aloy 6267 alloys, respectively, effectively prevented reactions with cold water (20° C.) and hot water (i.e., 70° C.-90° C.) at standard atmospheric conditions.

In 2.0 M and 5 M HCl acid solution at 20° C., all four REE-Aloy metals react. The most delayed acid reactions occurred for REE-Aloy 6267 and REE-Aloy 6277. REE-Aloy 6062 and REE-Aloy 6079 observably form a neodymium-aluminate surface layer that prevents corrosion even in hot water. However, it reacts in HCl as predicted to form a stable Nd₃AlCl₃ phase (ΔH_(f)=−1.595 eV/atom) [2 and 3]. A similar reaction with HCl is expected for the REE-Aloy 5700, 5900, and 6300 series, where their surface aluminate oxide is predicted to form La₃AlCl₃, Pr₃AlCl₃, and EuAl₂Cl₈, respectively. The reactions of 2.0 and 5.0 M HCL with both neodymium and samarium are both instantaneous and vigorous.

1.6 Electron Microscopy (SEM/TEM) Analysis

Electron microscopy (i.e., SEM/TEM) analysis performed revealed that REE-Aloy 6062 and REE-Aloy 6267 each have a unique set of binary intermetallic phases within their matrices. FIGS. 1.6(a) i.-vii. shows the STEM and HRTEM images and resulting analyses from the REE-Aloy 6062 matrix. FIG. 1.6(a) i. shows a micrometer resolution EM scan of a region of the sample REE-Aloy 6062 matrix which, includes four separate grain structures labeled G1-G4. The distinction between pure (i.e., the unreacted) aluminum and the intermetallic Nd—Al species is clearly seen. The lighter contrast region (G2) is pure aluminum and, the darker regions G1, G3, and G4 being Nd—Al intermetallic phases. The confirmations revealed by STEM element-contrast scan and EDS QUANT, and HRTEM and electron diffraction are in FIG. 1.6(a) ii. and iii. and, in FIG. 1.6(a) iv.-vi.), respectively. Particularly, for the ‘G3’ grain, the STEM EDS QUANT atomic percentage suggests a NdAl₂ intermetallic phase (FIG. 1.6(a) iii). However, for the same grain, except for an unmatched diffraction pattern along a grain axis that cannot be indexed (FIG. 1.6(a) vi), the HRTEM and diffraction otherwise suggest the NdAl₄ intermetallic phase.

The NdAl₄ is not a predicted ground-state phase and is therefore predicted to decompose into Al and the ground-state phase NdAl₃. Moreover, NdAl₄ is an analog of the Al₁₁Nd₃ phase. Al11Nd3 is predicted to exist as two isomeric states, αNd₃Al₁₁ whose stability is only below 640° C., and the βNd₃Al₁₁ which, is stable between 640° C. and 950° C. [4, 5, and 6]. Nonetheless, the difference between the Nd—Al atom fractions measured by the EDS QUANT (32% Nd-68% Al) and the atomic ratio based on NdAl₄ (i.e., Nd₃Al₁₁) cannot be conclusively reconciled. However, by reasonable deduction, this invention concludes a new phase Ncl₅Al₁₁ (31.25% Nd-68.75% Al, atom fraction) for the Nd—Al intermetallic phases within the REE-Aloy 6062 alloy matrix. The measured melting temperature of the invented REE-Aloy 6062 alloy matrix is {tilde over ( )}1200° C. which is higher than the βNd₃Al₁₁ phase but within the range of NdAl₃ and NdAl₂ phase [4, 5 and 6]. Reference [2 and 3] predictions show that Nd₅Al₁₁ has a favorable ΔH_(f)=−0.488 eV and decomposes into NdAl₃ and NdAl₂, both ground phases, respectively.

The formation of the neodymium aluminate on the surface of the REE-Aloy 6062 alloy matrix was not confirmed by SEM/TEM measurements. The samples used in the SEM/TEM analysis surfaces were mechanically ground for cleaning. Thus, the grinding produced a surface layer with fine grain, different from the ‘G3’ grain as shown in FIG. 1.6(a) vii. However, electron energy loss spectroscopy (EELS) data from the surface layer and G3 grains indicates no difference between their chemical composition or bonding structures. A diffraction pattern measurement of the surface layer also suggests a similar phase to the G3 grain region.

FIGS. 1.6(b) i.-vii. shows the STEM and HRTEM images and the results from analyzing REE-Aloy 6267 matrix. FIG. 1.6(b) i. shows STEM scans of a region of the REE-Aloy 6062 matrix included in the boxed region of the sample. The EDS showed the SmAl₃ phase, but enough confidence from the electron diffraction of four (4) different zone axis to confirm the SmAl₄ phase. The EDS map quant, in general, need to consider several factors to be accurate and sometimes. Also, it often involves a standard sample to be used as a reference. FIG. 1.6(b) ii-FIG. 1.6(b) v. show four zones axes, confirming a native SmAl₄. Therefore, REE-Aloy 6267 are mixtures of Al+SmAl₄. The phase SmAl₄ has a near-ground-state predicted with ΔH_(f)=−0.348 eV/atom. The SmAl₄ phase is likely analogous to the Sm₃Al₁₁, similar to the NdAl₄/Nd₃Al₁₁ analogs. Sm₃Al₁₁ is predicted to exist above 1050° C. [4, 5, and 6]. The predicted 1050° C. agrees with the measurement in this work concerning REE-Aloy 6267 melting point at {tilde over ( )}1300° C. However, long range order, evident for crystalline solids, is revealed by the HRTEM diffraction patterns for the REE-Aloy 6267 intermetallic species in FIG. 1.6(b) ii-FIG. 1.6(b) v electron diffraction images. For the REE-Aloy 6267 Surface analysis, a multi-beam bright-field image clearly shows fine-grains in the top surface, similar to what is observed in the REE-Aloy 6062 surface matrix, in FIG. 1.6(b) vi. FIG. 1.6(b) vii shows the HRTEM image of the fine-grain surface structure and reveals a nano-crystalline layer that confirms O, Sm, and Al in two of three STEM EELs spectra analyses. The presence of O, Sm, and Al in this crystalline form indicates the robust perovskite or garnet, samarium aluminate surface layer. The confirmation is also revealed in the results of the preliminary corrosion study, i.e., Table 1.3, where REE-Aloy 6267 shows no reaction in water and is very slow to react with HCl.

1.7 Application Technologies of REE-Aloy Alloy Series

The applications of the REE-Aloy series extend to the structural metallurgy industry, where specific REE-Aloy alloys are used as a steel and aluminum replacement option. Ree-Aloy's innovative series have thermo-mechanical stability and other mechanical properties that rival carbon steel while weighing 20% less and have the corrosion-resistant benefits of aluminum. Therefore, industrial and structural components usually manufactured from steel or aluminum are easily replaceable with a specific REE-Aloy alloy with additional benefits. Thus, REE-Aloy replacement options include but may not be limited to the automotive, aircraft, jet turbines, building-construction, and marina-vessel industries.

When any REEs with high neutron-absorption probability is in the form of a REE-Aloy alloy series, the potency to revolutionize the current state-of-the-art control rod absorber technology. The revolution over the current technology in terms of applicability, functionality, competitiveness, and radioactive waste-stream management to reduce environmental impact is irrefutable. For example, the novel matrices of the REE-Aloy 6200 (samarium-aluminum) alloy series promises practically limitless service life performance with invaluable accident-tolerant potency. The lifetime in-core service performance is attributed to the fact that many samarium isotopes (stable and radioactive) possess a high neutron absorption probability for fission control. Stable samarium-149 is the primary neutron-absorber for samarium. A unique characteristic of samarium-149 is revealed when it is exposed to neutron irradiation. The Sm-149 transmutation pathways lead to other samarium isotopes with significant capture probabilities. They also continue to nuclides of two different elements, namely europium and gadolinium, with more massive neutron capture probabilities. For instance, beginning with the primary neutron capturing isotope Sm-149 (40000 barns) under neutron irradiation, the possible transmutation paths, including radioactive-decay, are depicted in the diagram, FIG. 1.7. Except for Sm-154, Gd-154, and Gd-156, all other nuclides shown on FIG. 1.7 has significantly large neutron-capture probabilities for fast and thermal neutrons. Therefore, the depletion of Sm-149 by neutron irradiation can eventually produce by transmutation stable nuclides such as Gd-155 and Gd-157, with massive neutron capture probabilities.

REE-Aloy 6200 series shows excellent corrosion-resistant for clad-free control rod application in almost any reactor core. It is expected to be swelling-resistant during irradiation and observed to have a high toughness factor. A high toughness factor suggests less tendency for creep and heat deformation during irradiation. On the other hand, the REE-Aloy 6600 (dysprosium-aluminum) series, possibly a more economical option, offers similar mechanical and corrosion durability but less service time and neutron worth as control rod material. Although REE-Aloy 6675-6680 matrices with a slow-neutron (i.e., thermal) capture probability of 295 barns is much less than REE-Aloy 6275-6280's 1895 barns, it still has more neutron worth than the current Silver-Indium-Cadmium alloys of 220 barns used currently in commercial PWR cores. The control-rod application for nuclear reactors aspect of this invention, therefore, extends to the REE-Aloy 6300 (europium-aluminum) and 6800 (erbium-aluminum) series. Table 1.7(a) shows the comparisons for various REE-Aloy series neutron-absorber options to the current control rod absorber technologies for some critical metrics.

TABLE 1.7 (a) Comparison of Current State-of-the-Art Control Rod Absorbers to REE-Aloy Series Thermal Corrosion- Melting neutron-capture Resistant Nuclear Control Rod point cross-section Surface- Reactor Core - Type Absorber (Material) (° C.) (barns) layer Cladding Application Boron-carbide 2350 614 none steel BWR, PWR, Test & Research Silver-indium-cadmium 850 202 none steel PWR Ree-Aloy 6675-6680 1446 295 metal-oxide none BWR, PWR, Test & Research, (dysprosium-aluminum) Naval, SMR, MSR, LMCR series Ree-Aloy 6375-6380 1050 1472 metal-oxide Ree-Aloy BWR, PWR, Test & Research, (europium-aluminum) Naval, SMR, MSR, LMCR series Ree-Aloy 6275-6280 1480 1895 metal-oxide none BWR, PWR, Test & Research, (samarium-aluminum) Naval, SMR, MSR, LMCR series Ree-Aloy 5975-5980 1480 51 metal-oxide none Tests & Research, SMR (erbium-aluminum) series Hafnium 2,233 104 metal-oxide none BWR

REE-Aloy series with low neutron-absorption probabilities also have essential applications in nuclear reactor technology. The large vessel in which the reactor core (i.e., fuel) is contained is called the reactor pressure vessel (RPV). RPV is commonly made of a variety of steel called copper-containing bainitic (carbon) steel. However, RPVs must have robust thermo-mechanical properties as well as corrosion resistance. Therefore, the vessel's body is typically made of carbon steel, and the exterior is clad with stainless steel to mitigate corrosion by being in contact with the coolant. However, neutron irradiation of the iron and nickel in the vessel produces long-lived radioactive Nickel-59 and Nickel-63 with half-lives of 76000 and 101 years, respectively, which causes disposal concerns. Retired RPVs are often too expensive to dispose of and become a facility's legacy waste. REE-Aloy 3975-3980 (yttrium-aluminum) series, 5775-5780 (lanthanum-aluminum) series, 5875-5880 (cerium-aluminum) series, and 5975-5980 (praseodymium-aluminum) series, are all potentially suitable materials for replacement steel in commercial PWR and BWR RPVs manufacturing. Table 1.7(b) shows their comparison to current steel technology and aluminum.

TABLE 1.7 (b) Comparison of Reactor Pressure Vessel material to REE-Aloy Series Thermal Corrosion- Melting neutron-capture Resistant Reactor Pressure Vessel point cross-section Surface- Reactor Core - Type Material (Metal) (° C.) (barns) layer Cladding Application Aluminum 660 0.23 metal-oxide — Test & Research Ree-Aloy 3975-3980 1490 0.57 metal-oxide — BWR, PWR, Test & Research, (yttrium-aluminum) Naval, SMR, MSR, LMCR Ree-Aloy 5875-5880 1480 0.36 metal-oxide — BWR, PWR, Test & Research, (cerium-aluminum) Naval, SMR, MSR, LMCR Ree-Aloy 5775-5780 1405 3.05 metal-oxide — BWR, PWR, Test & Research, (lanthanum-aluminum) Naval, SMR, MSR, LMCR Ree-Aloy 5975-5980 1480 3.84 metal-oxide — BWR, PWR, Test & Research, (praseodymium-aluminum) Naval, SMR, MSR, LMCR Steel 1375-1530 3.1 Austenitic — BWR, PWR, Test & Research, Stainless- Naval, SMR, MSR, LMCR Steel

REE-Aloy alloy series can be applied as the basis for potential advancements in rare-earth magnets by significantly improving the curie (demagnetizing) temperature, melting point, and corrosion resistance. Specifically, REE-Aloys 3900, 5800, 6600, and 6700 series can be used as an essential constituent in the iron and cobalt matrix for extensive advancement in REE-Aloy permanent magnet technology. These REE-Aloy series can form similar phase structures as the well-known Nd₂Fe₁₅B₂ neodymium magnets. By replace the boron constituent with aluminum, the curie temperature increases along with the melting point of the material [10]. For instance, energetically favorable REE-Aloy-based phases with permanent magnet applicability predicted using Ref [2 and 3] for a REE-Aloy matrix dissolved in solid ferromagnetic matrix as a solid solution such as Y₂Al₃Fe₁₄ (ΔH_(f)=−0.126 eV/atom), Y₂Al₃Co₁₅ (ΔH_(f)=−0.1026 eV), Ce₂Al₂Co₁₅ (ΔH_(f)=−0.102 eV) Gd₃AlNi₈ (−ΔH_(f)=−0.427 eV/atom), Dy₂Al₂Fe₁₅ (ΔH_(f)=−0.089 eV/atom), Dy₂Al₃Fe₁₄ (ΔH_(f)=−0.128 eV/atom), Ho₂Al₂Fe₁₅ (ΔH_(f)=−0.095 eV/atom) are all more stable than the Nd₂Fe₁₄B phase with a ΔH_(f)=−0.059 eV/atom. Additionally, the potential application of REE-Aloy is in the electronic and microwave engineering industry. In particular, for the development of micro-components such as metal-oxide-metal (MOM) capacitors and on-chip transformers. The electrical properties of the REE-Aloy series are likely comparable to aluminum. For MOM capacitors, the robustness of the Ree-aluminate (Ree_(x)Al_(y)O₂) surface oxide layer formed between the REE-Aloy metal layers can offer extensive electronic signal and frequency stability for the component. Most perovskite-type aluminates (Ree_(x)Al_(y)O₂) are insulating as far as electrical properties [11, 12]. Similar benefits can be expected for on-chip transformers.

REFERENCED PATENTS

1. Patent: CN101906604B

2. Patent: U.S. Pat. No. 5,037,608A

3. Patent: CN103924127A

4. Patent: U.S. Pat. No. 3,490,900A

5. Patent: U.S. Pat. No. 2,771,369

6. Patent: U.S. Pat. No. 4,108,645A

7. Patent: U.S. Pat. No. 7,854,252B2

OTHER REFERENCES

1. H. M. King, REE—Rare Earth Elements and their Uses The demand for rare earth elements has grown rapidly, but their occurrence in minable deposits is limited, https://geology.com/articles/rare-earth-elements/ accessed: Sep. 12, 2021

2. Saal, J. E., Kirklin, S., Aykol, M., Meredig, B., and Wolverton, C. “Materials Design and Discovery with High-Throughput Density Functional Theory: The Open Quantum Materials Database (OQMD)”, JOM 65, 1501-1509 (2013).

3. Kirklin, S., Saal, J. E., Meredig, B., Thompson, A., Doak, J. W., Aykol, M., Ruhl, S. and Wolverton, C. “The Open Quantum Materials Database (OQMD): assessing the accuracy of DFT formation energies”, npj Computational Materials 1, 15010 (2015).

4. P. Franke, D. Neuschutz, “Scientific Group Thermodata Europe (SGTE) Al—Sm and Al—Nd (Aluminium-Neodymium, and samarium). Binary Systems. Part 5: Binary Systems Supplement 1. Landolt-Börnstein—Group IV Physical Chemistry (Numerical Data and Functional Relationships in Science and Technology), vol 1965, Springer, Berlin, Heidelberg.

5. K. A Gschneidner, Jr and F. W. Calderwood, Bulletin of Alloy Phase Diagrams, Vol 9, No. 6, 1988.

6. R. P Elliott and F. A Shunk, Bulletin of Alloy Phase Diagrams, Vol 2, No. 2, 1981.

7. Certificate of analysis, American Elements 99.99% (REM) Neodymium and samarium Metal Shots, GD-M-04RM-SHO.10M MS, Lot #1281397249-282.

8. T. I. Al-Muhimeed, et al., Advances in Material Sciences and Engineering, Vol. 2018, ID 9128696. (2018).

9. I. de Francisco, et al., Solid State Sciences 13, 1813-1819, (2011).

10. E. Weitzer, K. Hiebl, and P. Rogl, Journal of Applied Physics 65, 4963 (1989).

11. A. Szysiak et.al, Journal of Alloys and Compounds, 509(35): 8615-8619, (2011).

12. A. A. Demkov and A. B. Posadas, Integration of Functional Oxides with Semiconductors, DOI 10.1007/978-1-4614-9320-4, (2014) New York, Springer-Verlag. 

1. A method, described in Section 1.3, that produces monolithic binary rare-earth-element (REE)-aluminum (Al), intermetallic alloy with composition in the range of 30 wt %≤REE≤wt 85% with the balance aluminum.
 2. A method as in claim 1 utilizing a multi-layered melting vessel in FIG. 1 that consists of an exterior isolation vessel with an inner insulation layer, and an inner melting vessel that contains a pure alumina reaction vessel with its inner surface coated with an REE-aluminate layer of the general formula REE_(x)Al_(y)O_(z) for use within an oxygen-free environment.
 3. A method as in claim 1 producing a matrix with a monolithic binary rare-earth element-aluminum alloy having its purity greater than 90.0 weight percent.
 4. A method as claim 1 producing REE-aluminum alloy with optimal thermo-mechanical stabilities greater than or comparable to the alloying rare-earth element and that of aluminum.
 5. A method as in claim 1 producing corrosion resistance REE-aluminum alloy that exceeds that of the binding REE and that of aluminum due to the formation of surface perovskite and or garnet type REE-aluminate of the general formula REE_(x)Al_(y)O_(z).
 6. A system of monolithic binary rare-earth-element (REE)-aluminum (Al) alloy series in the mass range 30 wt %≤REE≤wt 85% with the balance being aluminum defined as REE-Aloy xxyy, where xx is the REE atomic number and yy is the REE weight percent, that has direct applications as superior alloy technology as replacement options for steels, aluminum, and titanium alloy, where, REE=Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Lu.
 7. A tertiary alloy containing 50 wt % or more of a monolithic binary REE-aluminum REE-alloy matrix as in claim
 6. 8. The series of monolithic binary rare-earth-element (REE)-aluminum (Al) alloy claim 6, having applications as superior alloy technology for advanced clad-less nuclear reactor control rod and neutron-absorber material, where REE=Sm, Eu, Dy, Er.
 9. The series of monolithic binary rare-earth-element (REE)-aluminum (Al) alloy in claim 6, having applications as superior alloy technology for clad-less nuclear reactor pressure vessel manufacturing, where REE=Y, La, Ce, Pr.
 10. The series of monolithic binary rare-earth-element (REE)-aluminum (Al) alloy in claim 6, having applications as advanced materials for use as metal-oxide-metal (MOM) capacitors and On-chip transformers components technology utilizing an REE-aluminum REE-Aloy alloy as a conductor and its REE-aluminate (REE_(x)Al_(y)O₂) surface layer as a dielectric medium, where, REE=Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Lu.
 11. The series of monolithic binary rare-earth-element (REE)-aluminum (Al) alloy in claim 6, having the application in making permanent magnets material, using an REE-aluminum REE-Aloy alloy series in combination with iron, cobalt, or nickel, where REE=Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Lu. 